At a driving range, a golfer wishing to practice his golf swing places a golf ball on a tee inserted into the tee hole in, or upon the surface of, a golf mat practice mat and attempts to place his feet in an appropriate position on the mat so as to properly align himself to swing a golf club to drive the golf ball in a desired direction. If we consider one reference line passing in just in front of the toes of the golfer's feet and another reference line perpendicular to the first line passing through the ball, then the appropriate position for the golfer's feet is determined by the distance of the first reference line from the ball as well as position of the intersection of the two reference lines relative to the golfer's feet.
While reference lines could be incorporated into the surface of the mat to aid in the placement of the golfer's feet, mats incorporating reference lines are not normally found at driving ranges, perhaps because mats are typically rotated periodically to even out wear, necessitating a large number of sets of reference lines. Further, several lines would be needed in each set to accommodate golfers of varying size and the configuration of the reference lines would vary with the type of golf club used, even for the same golfer. For example, a mat incorporating such reference lines is disclosed in Dionne et al., U.S. Pat. No. 5,645,494.
A number of other golf practice mats are known for aligning a golfer's swing. For example, Fowler, U.S. Pat. No. 3,868,109, Richards, U.S. Pat. No. 4,101,130, Menendez, U.S. Pat. No. 3,550,946, and Bott, U.S. Pat. No. 4,805,913 disclose such mats. In each case, the golfer wishing to use such mats at a driving range must rely upon the operator of the driving range to provide such mats or must transport his own mat to the driving range, at best an inconvenience.
Other golf swing alignment aids are known. For example, Trosko, U.S. Pat. No. 3,580,584, Medders, U.S. Pat. No. 3,920,248, Blanchard, U.S. Pat. No. 4,478,422, Poirier, U.S. Pat. No. 4,539,815, Beatty, U.S. Pat. No. 5,415,407, and Balson, U.S. Pat. No. 5,437,448, disclose various templates, frames, or arrangements of cords or strips.
Of the alignment aids mentioned, only Beatty, U.S. Pat. No. 5,415,407, in FIG. 5 thereof discloses an apparatus suitable for use with a golf mat 30. However, it appears that the mat 30 must have specific characteristics, such as an aperture 37 near the tee 38 and an over-all square shape, which may not be present in golf mats found at all driving ranges (most golf mats in use are now octagonal). Further, strips 40 do not appear to be repositionable for golfers of varying size and for the use of a variety of golf clubs and are held in place by springs 39 and J-hooks 36, both of which protrude somewhat above the surface of the mat 30 and so may interfere with the golfer's swing.
Sutton, U.S. Pat. No. 5,042,815, discloses a golf swing alignment device including a mat 28 and several flexible cords 22, which act as reference lines, and frames 26 for holding the cords 22 in place. The cords 22 and frames 26 appear to be selected for the mat 28 of a particular size as the cords 22 are not specifically elastic. Further, the frames 26 appear to protrude above the surface of the mat 28, possibly leading to interference with the golfer's swing. As well, if the golf ball is accidentally hit along the surface ("topping the ball"), then the ball could be deflected by the frames 26 cause injury to bystanders.
To the knowledge of the inventor, a compact, easily transportable, and inexpensive golf swing alignment apparatus for use at driving ranges with or without the golf mats that happen to be present has not been available previously.